Preheat the oven to 220C/ 200C F/Gas 7. Rub the chicken thighs with the mustard and season generously with salt and pepper. Drizzle them with olive oil, pop them in a roasting tray and transfer to the oven for 20 minutes.
Meanwhile, remove the sweetcorn kernels from the cobs. (See Cook’s Note, below.) Warm half the butter with 1tbsp oil in a large saucepan. Add the sweetcorn kernels and heat them over a medium setting for 5-6 minutes until partly cooked. Tip in the stock or water and add the stripped cobs too (they add extra flavour to the stock). Bring to a simmer for 10 minutes to ensure the kernels are cooked through.
Once the chicken has had 20 minutes in the oven, add the grapes and rosemary to the tray. Drop the temperature to 200C/180C F/Gas 6, then put the tray back in the oven for a final 15 minutes.
Remove the cobs from the pan of corn and discard them. Whisk the simmering stock until it is spiralling. Slowly add the polenta, so it doesn’t all clump together. Once the polenta is all incorporated, keep whisking until it thickens to the consistency of mashed potato.
Take the pan off the heat and whisk in the parmesan, the remaining butter and plenty of black pepper. Taste and adjust the salt levels to your liking.
Place a frying pan over the heat and quickly wilt the spinach or chard with a pinch of salt. If the leaves are still wet from washing, you won’t need any oil in the pan.
Spoon the polenta on to plates followed by the spinach or chard, chicken and the grapes, then pour all the juices from the roasting pan over the top.
COOK’S NOTE
To remove the kernels from the corn cob, peel away and discard the outer husks and silks. Cut the end off the cob to make a flat base, stand it upright and use a sharp knife to cut away the kernels.
Recipes and photographs taken from the Riverford cookbook: easy evenings, photography by Smith & Gilmour (Carnival, £22)
